i had the same problem....but with my body lift the hole in the floor wasnt big enough, and under tork the case would rotate, hit the floor panel and shift it outta loc. very odd, but something to keep in mind

Check this thread for more ideas: <a target="_blank" href=http://coloradok5.com/forums/showflat.php?Cat=&amp;Board=blazer4x4&amp;Number=325774&amp;page=0&amp;view=collapsed&amp;sb=5&amp;o=7&amp;part=>http://coloradok5.com/forums/showflat.php?Cat=&amp;Board=blazer4x4&amp;Number=325774&amp;page=0&amp;view=collapsed&amp;sb=5&amp;o=7&amp;part=</a>

<font color=black>HarryH3 - '75 K5</font color=black>
<a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
It's a great day to be alive...

had kind of same problem, only in 4hi prior owner had put in a POS t-case drop found that linkage was not adjust correctly. Don't know if you have a drop but check. does your gear indicators line up on your t-case shifter?

Useful Searches

>
About Us>
>
In May of 1999 CK5 started out as a tribute to America's favorite 4x4 utility truck. Since then it has grown to be
a leader among full size Chevrolet K5 Blazer and GMC Jimmy web sites across the Internet. CK5 has since expanded
to include the C/K series GM Truck and Suburban as well as past and present GM models.
>>
With its technical articles, factory specifications, photo gallery, classifieds, active message forum, product
reviews and original automotive content it's an unbeatable source.